The Emergency Airway National Review Course in Emergency Medicine Kirk Magee MD, MSc, FRCPC...
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Transcript of The Emergency Airway National Review Course in Emergency Medicine Kirk Magee MD, MSc, FRCPC...
The Emergency Airway
National Review Course in Emergency Medicine
Kirk Magee MD, MSc, FRCPCAssociate Professor
Dalhousie Department of Emergency Medicine
Outline:
• Recognition: is this an airway question?
• Cases
Case
• A 35 year old female presents to the ED with an altered LOC. She was found surrounded by empty pill bottles
• Vital Signs: HR 130, BP 115/78, sats 98%, GCS 6/15
• Is this an airway question?
Types of Airway questions
• Recognition of the need for an airway• Description of RSI and recognition of
relative contraindications• Recognition and management of a
difficult airway• Post intubation management• Approach to the failed airway
How to drive an examiner nuts…
• “I would perform an RSI with a double set-up”
Exam triggers to the difficult airway:
• Morbidly obese• Trauma to head or neck• Burns• Stridor• Prior unsuccessful attempts• Asthma• Anaphylaxis
Beware…
BMV
Laryngoscopy
Difficult Mask Ventilation
• Beard mask seal issues
• Obese lung/chest wall compliance
• Older head/neck position
• Toothless mask seal
• Snores/Stridor obstruction‘BOOTS’
Predicting Difficult Laryngoscopy and Intubation
MMAP the airway:• Mallampati and Measure
3-3-1
• A-O extension
• Pathologic conditions
‘MMAP’
Lets get ready to rumble!
Cases
Case 1
• 34 yo asthmatic presents with severe respiratory distress
• Normal airway
• VS: 122, 32, 156/90
Special Considerations
• Percipitating causes:– Pneumothorax, mucous plug– Role of epinephrine
• Difficult/impossible to BMV• Permissive hypercapnea• Ketamine• Apneic oxygenation
Apneic Oxygenation
Pre-oxygenation combining high flow nasal canula and a non-rebreather mask• Measured inspired oxygen NRBM @ 15 lpm only
60-70%– Pt’s expired gasses are mixing with applied O2 in
nasopharynx
• High flow nasal O2 flushes the nasopharynx with O2
– When pt inspires, inhale higher percentage of inspired O2
• Small changes in FiO2 create dramatic changes in the availability of O2 at the aveolus
Apneic Oxygenation
• Alveoli will continue to take up O2 even without diaphragmatic movments
• Optimal circumstances: PaO2 can be maintained at > 100 mmHg for up to 100 minutes without a single breathe!
“NO DESAT”
Nasal Oxygen During Efforts Securing A Tube
“If you enter the exam as a resident, that is how
you will leave, but if you enter as a consultant…”
Be decisive!
Case 2
• 4 yo presents with a 3 day hx of fever and “flu-like” symptoms
• Unable to arouse• VS: 139, 6, 60/40
Special Considerations
• Not just “little adults”
The Pediatric Airway
• Smaller airway• Large occiput• Tongue is larger• Larynx is relatively cephalad in position• Epiglottis is more floppy• < 10 yrs, narrowest portion of airway is
below vocal cords• Higher basal metabolic rate• bradycardia
Important pediatric numbers:• ET Tube size:
• ET Tube depth:
Age
4
Age
2
+ 4
+ 4
Breslow Tape
Case 3
• 26 yo Type 1 diabetic
• Florid DKA, not protecting his airway
• VS: 127, 28, 95/66, 95%
Special Considerations
• Hyperkalemia• Post-intubation still need high
respiratory rate– DKA– ASA overdose
Contraindications to Sux
• Hyperkalemia• Burns > 10% BSA• Crush injury• Denervation• Neuromuscular disease
– ALS, MS• Malignant hyperthemia
Case 4
• 50 yo pulled from burning car
• Significant burns to face, stridor
• VS: 112, 28, 132/88, 88%
Special Considerations
• Difficult airway• Toxicology
– CO– CN
MMAP: Pathological Obstructing Conditions…
e.g. Periglottic edema
e.g. Glottic trauma
MMAP: Pathologically Obstructing Conditions…
…with deep sedation may be impossible to BMV or intubate !!
Two Possible Scenarios
• Can’t Intubate• Can Ventillate
• Can’t Intubate• Can’t ventillate
What are your options?
• If not contraindicated, RSI may actually improve success rate– Double set-up
• Are you the right person, is the ED the right location?
• Awake intubation
‘Awake’ intubation
Advantages• Airway maintained
• Breathing continues• Stable
hemodynamics
Disadvantages• Can be difficult• Cooperation• Adverse reflexes
(GI/CNS/CVS)
…Intubation with topical airway anesthesia and light sedation.
Rescue device: Glide Scope®
Rescue ventilation devices: I-LMA
Rescue devices: Lighted Stylet
Rescue techniques
• Glide Scope®
• LMA• I-LMA• Lighted Stylet• Esophagotracheal Combitube• Retrograde Intubation• Fiberoptic Intubation
Can’t ventilate, Can’t intubate
Cricothryotomy Contraindications:
• Distorted neck anatomy• Pre-existing infection• Coagulopathy
• +++ difficult in pts < 10 yrs of age
Relative Contraindications!
What equipment do you need?• Scalpel• Tracheal dilator (Trousseau dilator) or
spreader• Tracheal hook• Portex or Shiley tube (No. 5-6 in
adult)
Decribe how you would perform a cricothyrotomy
Case 5
• 72 yo with altered LOC and urosepsis
• Normal airway
• VS: 124, 20, 70/40
Special Considerations
• CBA not ABC!– Maximize BP first
• Relative contraindication for etomidate?
“If only I had been a vet…”
Case 6
• 26 yo mountain biker “clothes-lined” on wire fence at high speed
• Pt is unable to talk; obvious respiratory distress
• Edema and echymosis evident at his neck
• VS: 115, 26, 160/85, 88%
Special Considerations
• The “most difficult” airway!• Patent airway may be lost with deep
sedation/paralysis• How does the scenario change with:
– Time from injury– Community vs Urban ED– “stable” vs. “unstable”
Your 1st attempt should not be in Ottawa at the exam centre!
Putting it all together
• Preparation – predictors of difficult BMV/laryngoscopy
• Preoxygenate – no BMV• Paralysis and induction agent• Placement of tube and confirmation• Post tube management
Putting it all together…Assess predictors of
difficult BMV/laryngoscopy
Pre-oxygenate
Paralytic/Induction Agent
Reposition
BURP
Bougie
Blade/ETT Change
Confirm Tube Placement
Rescue Techniques
Post Intubation Management
Cricothyrotomy
Unsuccessful
Unsuccessful
Unsuccessful
Difficult Laryngoscopy and Intubation: Putting it all together…
QuickTime™ and aCinepak decompressor
are needed to see this picture.